1. Field of the Invention
The present invention generally appertains to new and novel improvements in warm-air furnaces, boilers or the like gas-fired heating plants, and especially relates to a new and novel venting system for use with such heating plants.
2. State of the Art
Various and sundry venting systems for warm-air furnaces and the like heating plants are known in the art. All of such known systems function to carry off the fumes or products of combustion, which contain carbon monoxide, from the flue opening in the gas-fired furnace to the chimney flue. Most venting systems incorporate a back-draft diverter which is built adjacent to the combustion chamber of the furnace and within the jacket of the furnace and which functions to prevent a back draft from blowing out the pilot light in the combustion chamber.
But, in such conventionally vented heating installations, the gravity of the heat in the top of the boiler or furnace constantly allows the heated air to rise out of the chimney flue and to be replaced through the fresh air inlet by cool air, thus cooling off the combustion chamber of the boiler or furnace. Thus, conventional venting systems allow from one-quarter to one-half loss of heat which escapes by gravity of way of the chimney.
Attempts have been made, by way of draft hoods or regulators, to prevent the occurrence of down drafts through the chimney into the furnace. But such draft hoods or regulators also tend to reduce the temperature within the furnace chamber. The heat within the furnace chamber is drawn off or allowed to escape through the flue or chimney and, consequently, more combustion of fuel is required to raise the temperature within the furnace chamber.
One example of such a type of draft hood or regulator is disclosed in U.S. Pat. No. 2,165,811 issued to Peters on July 11, 1939. In such patented arrangement, the furnace chamber is connected to the chimney by means of a smoke pipe which extends upwardly from the furnace chamber and then horizontally in line with a connection into the chimney or into the flue thereof. The draft hood or draft regulator comprises a pipe member that connects the smoke pipe with the chimney connection and has a center portion provided with a baffle that extends downwardly into a vertical pipe which is mounted on the floor of the furnace room. Such pipe has a plurality of openings provided in its lower end portion.
In operation, the combustion products pass through the smoke pipe and then downwardly around the lower end of the baffle plate and then upwardly to the smoke pipe. In the event of a sudden draft, air is intended to be drawn into the vertical pipe through the openings in the lower end thereof while the baffle plate is intended to shield the burner and the pilot thereof from the draft.
In such patented hood or regulator arrangement, the hot air comes straight out of the furnace on a horizontal plane and escapes to the chimney or flue therein. In this respect, there is a cold air pressure within the vertical floor pipe that reaches to the level of the baffle with the draft hood and thus allows most of the hot air to escape up the flue.
Also such back draft diverter system performs little or no function of retaining the heat inside the furnace chamber once the burner has raised it. The stack or chimney temperature would be extremely high due to the escaping heat, slightly higher than the limit control setting of the furnace. The patented system does not hold heat in the furnace and cannot cut the fume temperature.
Such arrangement would never pass the safety standards of 400 parts, per million, of carbon dioxide, or less, content in the fumes as called for in Test Z 223.1 of the American National Standards Institute Inc. Such test is conducted with the flue blocked and with 106.25% of the normal gas pressure on the burner.
The drawing off of heat or the escaping thereof out the flue or chimney poses a serious problem of waste and also constitutes a source of air pollution.
Other types of venting systems, such as those disclosed in U.S. Pat. No. 931,824 to Weidenback et al and U.S. Pat. No. 1,655,858 to Donovan involve the utilization of check dampers.
Not one of such known venting systems deals with the problem of conservation of fuel while realizing a safe installation and operation is warm-air furnaces and gas-fired boilers. In other words, the two-folded problem of savings and safety and also, the task of reducing pollution.
In conventional methods of venting a gas-fired furnace, the gravity of the heat in the top of the furnace always permits the heat to rise out of the chimney flue and be replaced in the fresh air inlet at the main burners by cold air. This cools off the furnace chamber.
Furthermore, in conventional methods of venting, internal baffle means are utilized as back-draft diverters but none of these serve to form a heat lock within the combustion chamber so as to hold high temperature heat within the combustion chamber until the heat exchanger gives the heat off to the rooms serviced by the furnace.
And, in addition, none reduce the flue vent pipe temperature. But overheated vent pipes cause most, if not all, flue fires.
Also, known venting systems do not take into account flue stoppages, such as those caused by bird nests built in the chimney flue. Such stoppages block up the flue and, consequently, the lethal carbon monoxide fumes are pushed out into the building.
Finally, conventional venting systems must meet the standards set by the American National Standards Institute For Fire Protection and the American Gas Association and be adaptable for use in the limited furnace space usually found in modern home installations.